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Cisco Internetwork Operating System (IOS) is a family of network operating systems used on many Cisco Systems routers and current Cisco network switches originally designed by Sun Microsystems.
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perror(3c) [opensolaris man page]

perror(3C)						   Standard C Library Functions 						perror(3C)

NAME
perror, errno - print system error messages SYNOPSIS
#include <stdio.h> void perror(const char *s) #include <errno.h> int errno; DESCRIPTION
The perror() function produces a message on the standard error output (file descriptor 2) describing the last error encountered during a call to a system or library function. The argument string s is printed, followed by a colon and a blank, followed by the message and a NEW- LINE character. If s is a null pointer or points to a null string, the colon is not printed. The argument string should include the name of the program that incurred the error. The error number is taken from the external variable errno, which is set when errors occur but not cleared when non-erroneous calls are made. See Intro(2). In the case of multithreaded applications, the -mt option must be specified on the command line at compilation time (see threads(5)). When the -mt option is specified, errno becomes a macro that enables each thread to have its own errno. This errno macro can be used on either side of the assignment as though it were a variable. USAGE
Messages printed from this function are in the native language specified by the LC_MESSAGES locale category. See setlocale(3C). ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
Intro(2), fmtmsg(3C), gettext(3C), setlocale(3C), strerror(3C), attributes(5), standards(5), threads(5) SunOS 5.11 12 Jul 2007 perror(3C)

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strerror(3C)						   Standard C Library Functions 					      strerror(3C)

NAME
strerror, strerror_r - get error message string SYNOPSIS
#include <string.h> char *strerror(int errnum); int strerror_r(int errnum, char *strerrbuf, size_t buflen); DESCRIPTION
The strerror() function maps the error number in errnum to an error message string, and returns a pointer to that string. It uses the same set of error messages as perror(3C). The returned string should not be overwritten. The strerror_r() function maps the error number in errnum to anerror message string and returns the string in the buffer pointed to by str- errbuf with length buflen. RETURN VALUES
Upon successful completion, strerror() returns a pointer to the generated message string. Otherwise, it sets errno and returns a pointer to an error message string. It returns the string "Unknown error" if errnum is not a valid error number. Upon successful completion, strerror_r() returns 0. Otherwise it sets errno and returns the value of errno to indicate the error. It returns the string "Unknown error" in the buffer pointed to by strerrbuf if errnum is not a valid error number. ERRORS
These functions may fail if: EINVAL The value of errnum is not a valid error number. The strerror_r() function may fail if: ERANGE The buflen argument specifies insufficient storage to contain the generated message string. USAGE
Messages returned from these functions are in the native language specified by the LC_MESSAGES locale category. See setlocale(3C). ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |Safe | +-----------------------------+-----------------------------+ SEE ALSO
gettext(3C), perror(3C), setlocale(3C), attributes(5), standards(5) SunOS 5.11 31 Mar 2005 strerror(3C)

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